Along with Covid-19 virus, there is no end to the misinformation circulating around about the virus, immunity, and how the virus can be stopped. The following content is just an attempt to write basic content about viruses, Covid-19, and immunity.
A virus is a microorganism that requires another biological system to survive. These biological systems are plants, animals or bacteria.
Viruses use DNA or RNA to replicate inside another biological system called Host. DNA replication is a process by which a daughter strand of the double helix is formed from the parent strand.
Coronaviruses are RNA viruses (retrovirus) that use the biological machinery in a host cell to replicate or create more copies of itself. This is very important because of something called the central dogma of genetics or molecular biology: DNA > messenger RNA (mRNA) > Proteins.
Retroviruses use an enzyme called reverse transcriptase (RT) to convert RNA to DNA in host cells and get latched on to the DNA genome of the host cell.
So when a retrovirus infects a host cell, it converts the singe stranded RNA (transcribed) to double-stranded DNA copy called Provirus. This Provirus is integrated into the host cell DNA genome by a viral integrase enzyme.
Covid-19 virus enters a human cell by attaching itself to a protein on cell surface called ACE-2. The Spike protein is "a multifunctional molecular machine that mediates coronavirus entry into host cells". The Spike protein is important as it helps in developing a vaccine against the Covid-19 virus.
Viruses like Influenza Virus and Coronavirus enters through the nasal or oro-mucosal route. It destroys the epithelial cells, which function at a limited level as the first line of defence against such viruses. The virus then uncoats inside human cells, replicates inside host cells and force the infected host cells to release Virions.
Since Coronavirus is a new virus strain, human body will not have antibodies against such an infection. In general the following cells of our inmate immune system are involved in countering such virus infections:
Also, natural immunity against viruses are associated with Interferons, because they 'interfere' with viral replication. For example, in Polio prevention, IgG and IgE work as protective antibodies.
Eradication of viruses involve destroying the infected host cells. So, another type of cells called CD8-T cells are involved in destroying infected cells, along with NK cells and NKT cells, Destroying infected host cells prevents viral replication and in the end the elimination of the virus.
A virus is a microorganism that requires another biological system to survive. These biological systems are plants, animals or bacteria.
Viruses use DNA or RNA to replicate inside another biological system called Host. DNA replication is a process by which a daughter strand of the double helix is formed from the parent strand.
Coronaviruses are RNA viruses (retrovirus) that use the biological machinery in a host cell to replicate or create more copies of itself. This is very important because of something called the central dogma of genetics or molecular biology: DNA > messenger RNA (mRNA) > Proteins.
Retroviruses use an enzyme called reverse transcriptase (RT) to convert RNA to DNA in host cells and get latched on to the DNA genome of the host cell.
So when a retrovirus infects a host cell, it converts the singe stranded RNA (transcribed) to double-stranded DNA copy called Provirus. This Provirus is integrated into the host cell DNA genome by a viral integrase enzyme.
Covid-19 virus enters a human cell by attaching itself to a protein on cell surface called ACE-2. The Spike protein is "a multifunctional molecular machine that mediates coronavirus entry into host cells". The Spike protein is important as it helps in developing a vaccine against the Covid-19 virus.
Viruses like Influenza Virus and Coronavirus enters through the nasal or oro-mucosal route. It destroys the epithelial cells, which function at a limited level as the first line of defence against such viruses. The virus then uncoats inside human cells, replicates inside host cells and force the infected host cells to release Virions.
Since Coronavirus is a new virus strain, human body will not have antibodies against such an infection. In general the following cells of our inmate immune system are involved in countering such virus infections:
- Phagocytes
- Natural killer cells (NK cells)
- Mast cells and Basophils
- Dendritic cells
- NKT cells
Also, natural immunity against viruses are associated with Interferons, because they 'interfere' with viral replication. For example, in Polio prevention, IgG and IgE work as protective antibodies.
Eradication of viruses involve destroying the infected host cells. So, another type of cells called CD8-T cells are involved in destroying infected cells, along with NK cells and NKT cells, Destroying infected host cells prevents viral replication and in the end the elimination of the virus.
